pikuri-workspace

pikuri-workspace adds "operate on a directory tree" to pikuri-core agents: the +Pikuri::Workspace::Filesystem+ class that scopes filesystem access to an anchor + explicit readable / writable prefix lists (with optional ephemeral temp playground), the +Pikuri::Workspace::Confirmer+ seam (+AUTO_APPROVE+ + +TERMINAL+) for user-state mutations, and five tools wired to those seams: +Pikuri::Workspace::Read+, +Pikuri::Workspace::Write+, +Pikuri::Workspace::Edit+, +Pikuri::Workspace::Grep+, and +Pikuri::Workspace::Glob+. Self-contained — no shell execution; +Pikuri::Code::Bash+ ships in pikuri-code on top of these.